Conventional smart card modules can be provided with markings by means of special inks, holograms or barcodes, which markings can be read out either just visually or by means of special devices (for example UV measuring devices). Owing to their manner of production, said markings can be copied by means of appropriate know-how and effort. Visual read-out can be susceptible to errors. Using special equipment for the read-out can be complicated (place test item beneath test device, etc.) and/or—depending on the device required—expensive.